SOA Manifesto—Guidelines on What it Takes to be “Service-Oriented”

Lately, there's been a lot of discussion—if not outright arguments—over what service-oriented architecture (SOA) is, or is not, supposed to accomplish. Some analysts even say SOA—or at least what we've been led to believe was SOA—is dead.

Last month, at the International SOA Symposium in Rotterdam, I had the unique honor of joining a group of thought leaders and industry experts who sat down and worked to clear the air, once and for all, as to what it means to service-orient a system, and arrive at a consensus as to what SOA should mean to organizations. The result was a document called the “SOA Manifesto.” 

The work was done in rapid order, with an agreed-upon set of core values and guiding principles hammered out after just three days of intense debate. (You'll never see that in a standards working group, which typically takes years to arrive at common ground!) Even more remarkable was the diversity of the group, which consisted of independent analysts, writers, consultants and vendor representatives from Oracle, Microsoft, IBM and Tibco. For anyone concerned the vendor agendas influenced the Manifesto, I'll point out that one of the key proponents driving the language of the document was Burton Group's Anne Thomas Manes, who made quite a few waves earlier this year with her proclamation that “SOA is Dead.” 

Not everyone in the working group agreed on every point, but the values and guiding principles are intended to at least capture the spirit of SOA, which is intended to cut the dependencies between business processes and underlying technologies. In addition, the group sought to distinguish between “service orientation” as an activity and “service-oriented architecture” as the result of that activity. After all, nobody “did” Roman Architecture back in the day, right? It was the result, not the activity.

Here is the text of the SOA Manifesto:

“Service orientation is a paradigm that frames what you do.  Service-oriented architecture (SOA) is a type of architecture that results from applying service orientation.

We have been applying service orientation to help organizations consistently deliver sustainable business value, with increased agility and cost effectiveness, in line with changing business needs.

Strategic goals over project-specific benefits 
Intrinsic interoperability over custom integration

Shared services over specific-purpose implementations

Flexibility over optimization

Evolutionary refinement over pursuit of initial perfection

That is, while we value the items on the right, we value the items on the left more.
 
Guiding Principles

We follow these principles:

Respect the social and power structure of the organization.

Recognize that SOA ultimately demands change on many levels.

The scope of SOA adoption can vary.

Keep efforts manageable and within meaningful boundaries.

Products and standards alone will neither give you SOA nor apply the service orientation paradigm for you.

SOA can be realized through a variety of technologies and standards.

Establish a uniform set of enterprise standards and policies based on industry, de facto, and community standards.

Pursue uniformity on the outside while allowing diversity on the inside.

Identify services through collaboration with business and technology stakeholders.

Maximize service usage by considering the current and future scope of utilization.

Verify that services satisfy business requirements and goals.

Evolve services and their organization in response to real use.

Separate the different aspects of a system that change at different rates.

Reduce implicit dependencies and publish all external dependencies to increase robustness and reduce the impact of change.

At every level of abstraction, organize each service around a cohesive and manageable unit of functionality.”

Joe McKendrick is an author, consultant, blogger and frequent INN contributor specializing in information technology.